ADS Environmental Services IETG FlowHawk QR 775012 A4 - Manual (Page 53)

System Overview 2-17
the velocity sensor, and the signal received is the reflection of the
sound wave (emitted by the velocity sensor) off the particles.
Based on this information, the sensor determines the peak velocity
of the oncoming flow. Profile calculates an average velocity from
this peak by applying a user-defined average-to-peak ratio.
Ultrasonic Depth Sensor
The Ultrasonic Depth Sensor with a standard 9.1-meter (30-ft) cable
(p/n 8K-CS3-V0-XX-30) mounts at the crown (soffit) of the pipe
and measures ultrasonic depth. This sensor also is available with a
pressure depth capability.
Ultrasonic Depth Sensor
Ultrasonic Depth Sensor
This sensor first transmits sound waves from the sensor face to the
surface of the flow, and then these sound waves return to the sensor.
The monitor measures the time elapsed between transmission and
reception of the reflected sound signal. Based on the elapsed time
and the speed of sound, the monitor determines the range. The
range represents the distance between the sensor face and flow
surface. The monitor calculates the depth of the flow by subtracting
the range from the pipe diameter. It compensates for the speed of